And one-fourth to evbsetz e



IVI. R. WOLFARD.

- INTERNAL CONBUSUUN ENGINE..

APPLICATION FILED FEB 5. 1912 I Patented June 3, 1919. l

3 SHEETS-SHEET l M. R. WULFARD. INTERNAL CoMBUsHoN ENGINE,

APPLICATION FILED FEB. 5. 1912.

Patented J une 3, 1919.

3 SHEETS-SHEET 2.

M. R. WOLFARD.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED rri.5,`1912A 1,305,577. Patented um 3, 1919. I n 3sHEETs-sHET 3.

UNITED STATES PATENT @FFM-EEG MERL R. WOLFARD, F CAMBRIDGE,MASSACHUSETTS, ASSGNOR OE ONE-FOURTH TU LEROY A. AMES, OF SPENCER,MASSACHUSETTS, AND ONE-FOURTH TG EVERETT Eil.

KENT, 0F NEWTON, MASSACHUSETTS.

INTERNAL-COMBUSTION ENGINE.

Specication of Letters Patent.

Patented June 3, lti

Application filed February 5, 1912. Serial No. 675,538.

To all iii/1,0ml 'it may concern.'

Be it known that l, MiniL R. loiirAiu), a citizen of the United States,residing at Cambridge, in the county of Middlesex and State ofMassachusetts, have invented new and useful Improvements inInternal-Coinbustion Engines, of which the following is a specification.

This invention relates to improvements in i0 internal combustion.engines, being here illustrated inore particularly as it inay be appliedto a two cycle engine using heavy oil fuel. although the invention orsuitable parts of it inay be applied to various types i5 of engines, andto engines working on various cycles, and with various kinds of fuel.

It .is the object of the invention to iinprove on preceding engines byproviding an inn crease of capacity in engines of given size or weight;an. increase of etliciency, both thermodynamic and niechanical; .areduc- -tioii of number of valves and inoving parts; :i generalsiniplification of the mechanism as a. whole; and the elimination ofcertain lioubleson'ie mechanism, particularly that for producing thehigh pressure fuel-inject ing blast, which has hitherto been thoughtnecessary in some types of engines. It is also the purpose to attain theother advantages which result from the improvements herein disclosed.and to cover by Letters Patent such features or combinations as arenovel and patentable.

ln engines of the Diesel type, which represent the liigl'iest etliciencyheretofore attained, in practice, il' has been necessary to force thecharge of fuel oil into a bodyof air. so greatly compressed that it has`a temperature high enough to ignite the oil.

40 The oil has to be coim'ninuted and distrib-y uted in this body ofair, in order to get complete combustion quickly. This has hithertobeen/attemptedby using an auxil iary supply/of air of vet higherpressure,

but aty lower temperature, to blow in the oil, in the forni of spray.

It is the inventors belief that the attenuated character of theclearance space in engines as heretofore constructed, has been animportant cause of the universal failure, in

practice, to attain the efficiency which is theoretically possible. Atthe inner end of stroke, the air is distributed in a Wide thin'i'eilnote air.

layer over the'end of the piston. The fuel which enters earlier consumesthe air nearest the place of entrance. The fuel which ein ters laterthen finds itself surrounded by lhe combustion or products of thecoinbustion of the earlier fuel; and it cannot burn until the piston hasinoved out far enough for this later fuel to become iniXed with the Thisresults in retarded conibustion or afterburniiigy n n an engineembodying the present iiivention the clearance space, or what may forpresent purposes be called the clearance space, isso located at thebeginning of fuel adn'iission, and is so changed in its location whilethe admission of fuel contiiiues, that the lair that has beeniinpoiindeld and conipressed, ready for the next combustion,-

rushes past the fuel inlet valve as the fuel is entering. Thus eachparticle of eil, as it enters, linda at once an abundance of air for itscombustion. This rush of air may of itself tend to cause sub-division ofthe oil into niinuteparticles, somewhat as has the higher-pressure blastof air injected heretofore; but the insertion and spraying et fuel iseffected by simple mechanical means 'withorft any such higliei--pressureblast.

sizes is not necessary. Eachl cylinder has ports which are uncovered byits piston in the ordinary way at the end of strolre, the ports of onebeing connected to a supply of air, iinpelled by a slight pressure, andthe ports in the other cylinder being connected to exhaust, This airrushes through the eylinder it first enters, through the passage' intothe other cylinder, and thence tothe exhaust ports the-rein, with goedscavenging effect. The inward strokes of theA pistons, which then ensue,close the ports, both inlet and fifi les

titl

nii

i ierie pressure; and

ance space changes.

other eylinder.

"Y larly at the inegi-inning,

eiihauetin an improved manner or relation as hereinafter described so asto obtain a. nipleteeeai'eiigi 'andstartlirom atmofcompress the air thusiinpounded in 'the two cylinders until, at the inner end of stroke oithe leading "piston, 'the air is under high pressure read)v for theadmission and combustion ol the next charge of itiiel, and is containedmainly in the cyl inder which has the lagging' pieton, and in thepassage. fis the leiulinggv pieton then starts outward, the laggingpiston heiligA still in motion inivard, the location oi" the clearn Airrushes from the passage toward the leading n. gon. passing the fueladmission faire whien, at that moment, begins injeet oil. 'the airtalles up the oii in particles and carries it. burning into the leadingcylinder, where expansion occurs. This mixingv of oil and air may he ei:edited, if desired, by the inerhaniral distrilnlier of oil hereinaitrdescribed. ll'ie iiow from the other cylinder rontinuos until thelagging piston reaches its'inncr end of stroke. The admission of fuelmay Continue 'as long' as desired, the fuel burning; as it enters.. thelagging pieton starts out* ward, expansion occurs in both Cylindersuntil the exhaust opened inthe eine. eylinder, eiosely 'Tdilelized bythe inlet of air to the other. [is illustrated, the lagging pie ton andthe exhaust ports are in the smaller cylinder.

The inoven'ients of the tiro pistons relative to each other, and theconsequent timesl oi opening and closing the ports, are also titres oi'novelty. rFixe cylinder irliirh has the exhaust ports is illustrated asharing approximately one fourth et theeolnme oi the lt arranged with itsaxis oilset i om the diametrieal line of the rranlr einde; if piston rodis relativelyy sho and iti; por i relatirel),v longer than those in theother eyiinder. The result; if; tlrt, iii-- though the GraniteI remainalways at a, lixed angle apart, the relative positiorm oi'i` theirpistons rari', 'lilhe smaller, having eemplet'ed l greater spe-.eil thandoes the leading pistom and opens the exhaust ports before the largerpiston orient: the air inletI ports. .find its ensuing inward stro.slower than tht inward :stroke of the pieton, particu-- tuus holding,lthe enhauat open ior/,a period. attcr the air inlet ports have beeneloseil. .During this delay the air which has entered the inlet porte inthe larger cylinder compl` ly drives out air)7 'produits of eon'ibustionnot expelled lii/ the first rush, and leaves tl'ienconi'zents ol the twocylinders at approximately at .oepherie pressure at the beginning oi?eeniiireunion.`

The construction dose iin etlifonibustion at every ita inward stroke. ata certain interi'al ol' time after the larger mores outward with Leone??sion in two c \,'lindcrs; romplete exhaust land srarenrjing; a suitablecompression oll pure air lor the. next romlmstion; and arr-css ol.Eeuliiricnt air to over* particle olE tuel at iii-actually the instant otsuih partielcs entrance to the chamber with resultant continuous andcomplete combustion. This also allows the use of a hot comlmstionrhamher which further facilitates instantaneous and complete combustionas. for example, by vaporizine and ignitinje' the oil introdiu'ed,besides adding' marked thermal advantages which Cannot he obtained herevalves .and wat( .eoeled rages Ll'orm a large part of the inelesingWaits of the comliuution chamber. Any desired ignition system ma.)v beused.

No high-pressure air injection isrequircd to insert the luel. Nomechanically operated faire in required: either `ilor admission., or fortransfer of air, or i'or seareneingor for exhaust oit' the products etcombustion. The air used. `li'or searenging', and for the combuse tion,ent rs under small pressure such as may' he obtained, for example, oycrank` case rompreesion, or 'oy a` differential piston. Thetherniodynamir efficiency theoretically and practically obtainable isgreatly increased by the extended expansion secured through the novelarrangement of two pistons and the ports, without increasing the numberot' mechanical parts over those otherwise nece .rjf for mixing; thecharge.

bodiment of the invent-.ion7 various construetioiial details andarrangements being` omitted:

filigure i .is a. side elevation in central seetion through the tirocylinders; i v

" n end elevation in section on the is pfaiii in section on theline 3*-3jean end eleration oiE a detail env- '.i section on the lino 'l---l oiFig. 3; 5' is an elevation in sect ion showalternatii'e structure. oi" adetail, en-

` is a` eide elevation olE the saine;

J {StL-ft are diagrams of simultaneous pieton positions; and lil 7 is adiagram ot eoinpression and iansion ol the working tiuid.

{tori-ine' tothe drawings, It() represent/s the .larger eylindei-, il'the pieton therein, 12 the air inlet porta therein and i3 the crankshaft; towhich the piston connected. represents; the sine/ller cylinder,21 the lpiston therein and 92 the exhaust' ports therein. The crank ofthe larger piston is represented inclosed ijn a rase troni which aAioasliage .iti leads to the inlet ports l2. A. pesi-:agie eonneets thehead ende oit. the cylinders.

tliie 'in ige i" i ignition device 3l land l 53g for oil. er otheri'uele each of which may be of any suitable type. The drawings alsoindicate a pipe 33 leading from a pump 34 which may be convenientlylocated, for supply of fuel, the pump being driven by a cani 35 on themain shaft 13, by which oil is injected into passage 30 at predeterminedtimes.

The ignition device 31, as illustrated, consists of two nickel steelpoints between which an electric are is formed. One point 31 may bemerely a. knob on the under side of the passage 30, the other 31 beingadjustable toward-and from the knob 31 by means of a screw 36, and oneor both. of these being suitably insulated from the engine casing, as at37. The conductors leading to these two terminals arernarked 38, 38. Theignition device 31 is preferably arranged with its are in a recess 39 inthe side wall of the passage 30, so that it is not in the direct line ofiow through the passage, yet is within the line ot discharge trom thefuel injecting port 32, (Fig. 3). A special ignition device such as thisis not required it' the compression ot' air in the cylinders and passage30 be high enough, as in engines of the Dieseltype, because the airtemperature will ignite the fuel. ln engines working on lowercompression of air the ignition device may generally be cut out ofaction atter the engine has been running a few minutes, ignition being,then caused by the high temperature retained in the passage 30, thisbeing the system herein referred to as ignition by hotcombustionchamber. lt is only when the engine is starting, or is runningon very low pressures, that any special ignition device will be needed.

The iuel admission port 32 is a discharge orifice, exaggerated in sizein the drawing, for clcarncss, leading from a. hollow rotatingvhollow*"plug hi() which projects into the pas; 'sage 3d, being partlycinbcddcd 1n the side walls thereolI opposite the ignition device, asillustrated in Fig. l. rl`he interior ol' this plug` l() is filled withfuel vtroni the supply pipe 33 through a chanibcr l2 in the statioir aryblock l and an opening Lil in the rotating plug it). 'l`he plug seatedin this lblock on ground bearings fili, 5Fl, which prevent lcalcagc andhold its upper end clear from the surrounding hot walls. lt is rotatedat' a suitable speed by gears 45. ln an engine constructed asillustrated it is desirable to have thc discharge nozzle 32 move Whilethey fuel is being injected, so that, starting with its initialdirection ot discharge toward the ignition device and the entrance tothe large cylinder l0, it shall sweep toward the other end of thepassage 30 and the ventrance from the small cylinder 20. "ihe connectionto the main shaft 13 should be arranged. 'to produce the desired amountof rotation ot the plug 40 during the period in which admission of thefuel is to occur. The

rotation at other times is of' no consequence, because tlow ot :fueloccurs only when the pump 3l is actuated by the earn Consequently theremay be one or more complete rotations ol the plug between inflowperiods, without escape of oil. The inovcinent of the nozzle 32 whilefuel is being introduced distributes the incl through the air which isready in the passage and in the head end of the cylinder 2l). r[heoritice may, if desired, be annular as at 32 in Fig. 5, where aninterior spring hooktcnds to hold the valve in closed position on theoritice. When veriY sinall quantities of tiuid pass through a valve likethis, the distribution is made lnore certain by cinicentrating the l'lowat fixed points in the circumference, for which grooves BQ areillustrated, seen best in Fig. 5 where the valve has been removed. Thesegrooves extend through the valvesteni-guidc, whichis integral with thevalve seat. ri`he valve stein and guide may be slightl)v tapering. Thenthe stein can be ground to a perfect.- lit at the same time that thevalve is ground to its seat.

if preferred, the nozzle 32 may be held stationary, pointing toward theignition dev` vice, in which case the fuel that it delirers will betaken up as l the air rushes past it toward the outgoing piston in thelarge c vl inder l0. The tflescribed nioven'ient, in which the nozzle isswung gradually toward the direction iron'i which the air is moving,makes the distribution more rapid, because the inore remote air receivesits load oi fuel betere reaching the nozzle.

ln thctvpo of engine illustrated in Fig. 1 the pistons travel close tothe c vlindcr heads, expelling all't'he contents therco'liuto that spacewhich is in the passage 2&0, which remains lined iirlocation, and ishere referred to as lixed clearance space, and that space which is .inthe c 'rlindcr 2l) which ncrv be considered'as shitting into the othercvlindcr ll), as the lagging piston fil nflvanccs inward` and theleading piston ll1 nievesA outward. lthe fixed clearance space may be alarge or sinall proportion o'l the whole, according to the design olfthe engine, thc size ol passage Il() and thc degree o lag ol' the piston2l. li the lixcd clearance space be l'clativelv sulall, the rate otinjection ot l'ucl should bear sonie proper relation to the rate atwhich air is displaced troni the clearance in cylinder 20 and driveninto the clearance which is liornicd in cylinder l0 as its piston movesout, in order to secure good mixing and also to prevent the pressureresulting; troni coin bustion Jrfron'i becoming too great before eX-pansion occurs. it', on the contrary, the clearaiufevspace -lOberelatively large. it is more capable ot holding the air displaced fromcylinder 20; and the piston 2l may then be set so thatit lags lessbehind the other piston. rlhis makes an engine of someliti .Y pistonopel-1s the what greater y and shifting oi' clearance I capacity ofoutput. Also, the walls et the passage 30, where it is of largercross-section, absorb less heat during combustion and are cooled lessduring scavenging. Y l

An y suitable means may be employed for preventing' excessive heating ofthe cylinder walls, piston, etc., a Water jacket beingl illustrated,

Heut may be conserved by making-zi lining 4G el white iron Cruciblesteel or other tough and tenacious material chosen primarilyv for itsstrength and durability, without regard to its heat absorbingor heatconductingrv qualities and, suitably insulated from the walls, as by athin layer et asbestos 17. lll/larping olf this lining, by unequaleXpansion caused by the great heat, may be prevented Aby making;- one ormore saw-euts 48, which in the case of the cylinder or piston' plate maybe arranged radially, as illustratcd in Fig'. 8. lhe asbestos whichwould be thus exposed may be guarded from disintegration by a thininterveniugl plate oi metal 'lhe greatest changes of temperature thenoccur in this lining, but as it is only loosely attached, as by aAcentral bolt 50, as illustrated, (Fig. l), serious stresses are nottransmitted to 'the cylinder casing. Enough heat transmitted, however,to prevent eroi-heating of the said liixing. This relieves the outerwall :from much of the dis tortiou (ine to temperatures, and makes the`gradient of temperatures 'through the outside wall reasonably constant.This lining'. serves as a screen for heat inside the chamber,

"llie heat retained by this screen is in the ordinary type of enginecarried away by the water jacket. @wir/and above this valuableconserving oit heat in one cycle for the next, this het screen orlining' has two other important functions: it is an ideal vaporizer forliquid fuels; and it is an ideal iguiter and coinlnistiou chamber, leleparticle of oil can strike the Walls anywhere without being instantlyvaporizcd and. eou'lpletely burned, thus eliminating" ailitenburuing.-These adtantas"w l been claimed for i'iorcelain or. siinilai li uns,but such materials crack and are not practicable.

The arrancan ent et the piston and porte f' hanst in the two ture et theY piston en the produces the arrangement space, with quick mining; oitair and fuel, above described; but this 'lagging piston moves faster onthe out- Ward stroke, gaining on the leading' piston, se that it opensthe exhaust ports as soon as,v er preierably inst a little heitere, theleading air inlet ports. Eile accomplish in simple tvne et engine illus-`Jed, Talithout int" secondary miiltt inward stroke,

. ton travel, and being cylinder engines, to drive the small and laggingpistons, the lagging piston 2l is connected by a rather short rod 21 toa crank 23 hung on the end of the main shaft 13; and the cylinder 20 isoffset a little from the plane of the axes of the main shaft 13 and thelarger cylinder, which axes intersect in the usual Way. The distancewhich the smaller cylinder is thus offset, and the length oi the rodconnecting its piston to the crank, may vary according to circumstances,but it is believed that in the best practice the fornier will usually beequal to between onethird and two-thirds of the length of the crank 23,and the latter be from two to three times the length of said crank.Owing te 'l he confinement of the piston end of the con necting rod 2lto a line unsymnietrical With respect to the crank circle the tivo deadcenters of thatrod are not synnnctrically disposed, in the crank circle.In the diagrams, Fig. 6 the location of these tivo points is indicatedby the letters c and c respecH tively. Consequently, it' the crank i3rotate at uniform speed the piston 2l will make its outward strokesomewhat more rapidly than its inward. y

rlhc relation and the operation of these various parts to each otherWill be here eX- plained by the use of an illustrative eX- ample. Forthis purpose the following proportions of dimensions are assumed Lengthof crank of larger or leading piston seven and one-half inches, givingstroke of fifteen inches; the cylinder having a diameter of ten inches,and airv inlet ports extending thrce-it'ourths of an inch above thelowest peint 03E piston travel. Length of crank of si'nall or lagging'nist-on five inches, giving a piston stroke of approximately ten andone-halt inches; this cylinder having a diameter of inches, exhaustports extendingtwo inches above the lowest point of pisset with its axisparalicl to that of the other and three inches dis tant from the planeot`-that other cylinder and the main shaft; the sten tc its crank 23?being; twelve and onet in length; and the crank 23 ben eet eny the sameshaft with the crank but at an angle ci? lag with respect nto. lt willbe understood that lthese dimensions are purely for illustration, andmay beyaried in practice, not only by increasing or decreasing them,lout-also by changing' their proportions .teeach other within reasonablelimits in accordance with the principles of the invention. Figs. (ia-6illustrate diagrammatically the relations otthe parts to each other atsuccessive critical points in an engine having the proportions stated.These indicate the two cranks, 13 and 2'3, turning about the common axisrod connecting thisy 13, and connected i by reds l1 and 2l" respectivelyto .the pis' Storrs il. andi in cy moet?? diagrams show graphically thelocation and extent ot the ports, l2 and 22, and, by double lines, theportions of the crank circle in each case corresponding thereto. Therelative positions of the pistons 1l and 2l at the beginning ofcompression are indicated in Fig. 5a. The leading piston l1 has thenabout half completed its inward stroke, when the lagging piston 2l isclosing the exhaust ports 22. ln Fig. 6b the leading piston is at itsinward end of stroke, the stroke of the piston 2l being stillincomplete. Compression is completed; and fuel injection is about tobegin, to continue while the lagging piston completes its stroke andforces air past the fuel inlet. In Fig. 6 the piston 2.] is at itsinward end of stroke, and the leading piston 11 is well under way on itsoutward stroke. In Fig. 6d expansion has been completed; both pistonsare near their outward end oi stroke, the piston 2l having reached theexhaust ports, which is followed an instant later, Fig. 68, by thepiston 11 reaching air inlet ports. A period of retardation of thepiston 2l then follows while it is pass` ing its dead center, and whileits connecting rod is straightening into line with the axis of itscylinder until the position where this piston closes the exhaust ports.ln Fig. 6f the leading piston has been to its outward limit, and, on itsreturn, n inlet ports, while the crank of piston 2l has barely passedits outward dead center. The air inlet then remains closed and theexhaust remains open till the position shown in Fig. 6a is reached,after which the compression stroke is relatively rapid from the positionof Fig. 6a to that of Fig. 6l.

Beginning with the position indicated in Fig. 6a, which is the close ofexhaust, pure air is compressed in both cylinders starting at aboutatmospheric pressure. The maximum compression is reached approximatelyat the positionindicated in Fig. G", at which time the piston 11 beginsto move outward,

creating a space toward which the compressed air is driven, past thefuel inlet, by the still advancing piston 2l, till this lagging piston2l reaches its inward limit as indicated in Fig. 6c, after whichexpansion occurs in both cylinders. Upon the opening` of exhaust, whichit will be observed is very close to the end ot stroke ot both pistons,although the exhaust did not close till the inward stroke oi' the largerpiston was abou'J hall completed, contents oi' 'both cylinders flow out,impelled by expansion and by the inrush oi' air under slight compressionthrough the .inlet ports. A'ltcr the inlet ports are closed.. Fig. of,the exhaust-ports continue open. This enables the pressure in thecylinders to tall to atmospheric pressure, or to whatever level otpressure exists outside oi exhaust ports, in case a condenser or isuction device be employed. rlChe steady adis closing the air Vanceinward of the large piston pushes the recently admitted air ahead of it,which in turn pushes ahead of itself any products of combustion, outthrough the exhaust ports, so that when the exhaust ports inally close,F 6, both cylinders contain only pure air. rlhis is an advantage overprevious engines working by crank ease compression, becausel it is notpossible by the method ot' conn pression to transfer to the workingcylinder its full volume of pure air, owing to thedil ferences oipressure needed to effect; Itile transfer of airA from the atmosphereinto the crank case and from the crank case into the cylinder; and thefractional volume of air thus introduced `becomes mixed witlA the othercontents oi the cylinder; whereas in the present invention thefractional volume oi. air docs not become mixed, vbut remains while theother contents are expelled on the first portion of the inward stroke.

This purity of air results in a more rapid and complete combustion ofthe charge than heretofore customary in two-cycle engines, thus addingboth to the etliciency and to the capacity of the engine. i Indeed thecharge of air for combustion will be even purer than in the ordinaryfour-cycle engine, in which the inert gases are never expelled from theclearance and mix with the charge during the suction stroke.

The described arrangement ot' inlet and exhaust closing, and of exhaustopening, makes two other important additions to the economy heretoforeattained'in engines having pistonpperated valves, which will beexplained by reference to the theoretical. diagram, Fig. 7

In the diagram, Q3 represent. the conipression line of a working fluid;its expansion at constant pressure with addition of heat duringcombustion; and its adiabatic expansion thereafter, l-#Q being the lineof atmospheric pressure. The dis tance 1 2 represents the volume ordisplacement of a certain weight or quantity of air at atmosphericpressure.v 'It thisI same weight were at two pounds pressure thedistance 1 8 would indicate its displacement. In an engine beginning tocompress the assumed weight at two pounds would thereiore close itsexhaust valves-z at the point H; and the'lenglh of piston .stroke wouldbe substantially the distance tie-l according to customary practice inengines having piston operated valves. On the outward stroke the exhaustvalve would open at the same distance of piston movement, indicated at9. The work done would be indicated by the area S-*S-P-f). In anengineenibodying the invention, and holding'- thersame weight ol1 fluidat atmosphcricr pressure at the beginning of compression, the exhaustvalve would close at 2; the length ot stroke would be Q--l; and it thx`exhaust 'were to rename l claim 1- j l.. :\n internal combustion engineineludingg' in combi nation two cylinders and means to admit air to themfor the combustion; a passage continuously open between their head ends7suliicient in size for the main body ot air to pass throughit undernormal operating conditions without materia-l increase et pressure;pistons in the' cylinders, connected together to move the main body ofair through said passage at their` inner end of stroke; means to injectthe fuel charge directly into said main body of air at the inner end ofstroke gradually while it is so beingmoved; and means whereby the fuelignites and burns gradually during the continuance of its said injectioninto the main body of air.

2. n internal combustion engine including in combination two cylindersand means to admit air to them for the combustion; a passagecontinuously open between their head ends, sufficient in size for themain body ot air to pass through it under normal operating conditionswithout material increase ot'pressure; pistons in the cylinders`connected together to move the main body et air through said passage at.their inner end otstroke; a pipe holdinga column ot liquid t'uelextending;` continuously to said passage; a pump acting; on said "fuel,inject@ ing part thereotI gradually into said passage while' the mainbody et air is so being moved; and means whereby the fuel ignites andburns gradually during` the continuance ot its said injection into themain body et air.

.\n internalcombustion engine ineluding in combination two cylinders andmeans to admit air to them for the combustion; a combustion chamberconnecting their headeuds sullicient in cross-sectional area 'for themain body of `gases` to vpass through it under normal operatingconditions without material increase ot pressure; a piston in onecylinder haring approximately no clearance therein; there beingclearance to ',it in said chamber; a piston in the other c iliinderconnected to the tiret piston in such relation as to reach its inner endet stroke atter the first mentiomid piston has reached its inner end otstroke and is moving; ont ward; and means gradually to inject, [uelacross said chamber, while the main body ot air which is to support thecombustion thereot being' pushed past the point ot iuel injection by thesecond mentioned piston.

t. ln an internal combustion engine, the combination ot a workingcylinder, and a piston therein traveling to the head of the cylinderapproximately without clearance therein; another cylinder connectedtherewith` and a piston therein; there beinrc` a chamber affording spaceoutside of said working cylinder cooperating with space in the secondcylinder to provide capacity between the two pistons for holding themain body ot air for supporting combustion; means t0 inject fuelgradually into .said main body of air at a place near the junction ofsaid chamber with said working cylinder; whereby on the outward strokeof the ypistonY in said Working cylinder said main body of air fiowsgradually past said place where fuel is beinginjected while it is beinginjected; and means whereby the main combustion occurs immediately uponand progressively with said injection of tuel.

In an internal combustion engine the combination ot a working` cylinderand a piston therein traveling to its head approximately Ywithoutclearance therein; means inclosing space outside ot said workingcylinder tor .the main body of air compressed by sarl piston t'orsupporting the combusvtion, said space having a connection ot sut-,l

lieient size tor gases under normal operating conditions to flow from itto the said win-king cylinder without any material increase ot pressuredue to construction of passage: means to inject fuel gradually into saidspace ata place near the entrance therel'rom to said workingn cylinder,and displacing means adapted and organized to 'torce the main body ofair past the place of fuel injection during said fuel injection at anda'tter said pistons inner end of stroke.

o. ln an internal combustion engine' the combination of a workingcylinder and a piston therein traveling to its head approztimatelvwithout clearance therein; means inclosina'spaee outside of said Workingcylinder tor the main body of air compressed by said piston'forsupporting the combustion. said space having a connection of suf*{icient size :for gases under normal operating;` conditions to ilow fromit to the said working cylinder without any material increase ofpressure due to constriction of passau-e; means toinject fuel graduallyinto said space at a place near the entrance therefrom to said workingcylinder; displacing. means :ulaptrd and organized to torce the mainbody ol' air past the place of fuel injection durinr` said fuelinjection at and after said pistons inner end of'stroke; and meanswhereby ignition occurs appri-iximately ata the beginningl of saidinjection of fuel.

\ ln an internal combustion yengine the combination et two connectedcylinders and positirelyacting pistons therein, ending i their in 'ardstrokes at dillerent times, there whereby thermain combustionbegins-immediately upon entrance of fuel and continues progressivelywith injection of fuel into said main body of air.

8. In an internal combustion engine the combination of two connectedcylinders and positively-acting piston therein, ending their inwardstrokes at diiierent times, there being free connection between the.head ends of said cylinders, continuously open to the extreme end ofstroke in each cylinder and sufficient in size for passage of the mainbody of cylinder contents in either direction un der normaloperatingconditions without material increase of pressure; and means tointroduce fuel gradually while the pistons are -near their inward limitof stroke directly into said continuously open passage and\to cause itscombustion therem progressively with such introduction.

9. In an internal combustion enginel the combination of a cylinder, aWorking piston therein compressing air on inward stroke, there lbeingspace constituting clearance outside the cylinder to receive suchcompressed air, said space having a connection of suficient size forgases under normal operati` ing` conditions to How from it to the saidworking cylinder without any material increase of pressure clue toconstriction of passage; a fuel inlet to said space and means whereby,fuel is injected lthereinto gradually, immediately after each inwardstroke:

another cylinder, connected with said first cylinder through said space,and a piston in the .second cylinder', connected with the first pistonand displacing the clearance toward the first cylinder during fuelinjection; the whole organized and arranged so that the saiddisplacement of clearance operates substantially without producingexcess pressure above the normal pressures of the main compression anlcombustion and so that the `Fuel burns progressively as it is injected.

l0. In an internal combustion engine the combination of a cylinder, aworking piston therein compressing 'air on inward stroke; anothercylinder connected with the first and affording clearance for the aircompressed therein; a piston, in the second cylinder, connected with thefirst piston, and displacing the clearance toward the first cylinder;and a fuel inlet and means whereby fue] is injected into said clearancegradually, in'mlediately after each inward stroke ofthe working pistonand during said displacement of clearance -the whole organized andarranged so that the said displacement of clearance operatessubstantially without producing excess pressure above the normalpressures of the main compression and con bustion and so that the fuelburns progressively as it is injected.

11. In an internal combustion engine the combination of two cylinders, apassage con- .out of the direct currents 'maximum of hot gases bnstionengine, of two cylinders,

v controlling its ports,

:acotar/v necting them; a piston in each cylinder,- air ports' in onesupplying both cylinders; exhaust ports in the other, relieving" bothcylinders; said passage being a combustion chamber; one wall thereofhaving a recess formingl a hot ignition spt adjacent to but flowingthrough said passage to and from said ports.

l2. In an internal combustion engine, in combination, a cylinder andchamber connected therewith by a continuously open passage having a'cross sectional area lessthan thatof Said cylinder, but sufficient forthe main body of gases to pass through it under normal operatingconditions without any material increase of pressure, a piston in thecylinder; means to inject fuel gradually at the time of combustion anddisplacing means acting concurrently with the injecting means, the twocooperating to distribute said fuel progressively through the main 'bodyof engine contents.

13. Inan internal combustion engine the combination ot1 two connectedcylinders, one

being larger than the other, connected pis-r tons therein; a ho'tignition spot in the lpas sage connecting the cylinders; air ports forboth cylinders inthe larger; exhaustports for both cvlinders in thesmaller; whereby a and a minimum of cool air flow past the ignition spotat end of outward stroke; and means to inject fuel for immediatecombustion at the end of inward stroke.

14. In an internal combustion engine the combination of two connectedcylinders, pistons therein having cranks connected together, one laggingbehind the other; the cylinder' of the lagging piston being oii'set fromthe plane passingthrough the axis of its crank parallel to its own axis,exhaust ports in the offset cylinder, air ports in the other cylinderrelatively shorter than the exhaust' ports; and mea'ns to inject fuel atthe inner end of stroke.

15. The combination, in an internal coma passage ports in one, exhaustpiston in each cylinder and means whereby the pistonecontrolled exhaustports remain open on inward stroke until a considerable proportion ofthe combined piston displacement has occurred, and remain elosedon theout ward stroke until nearly the whoiecombined displacement hasoccurred.

16. In an internal combustion engine the` combination of two connectedcylinders; connected pistons in them, one lagging be-l hind .andv beingsmaller than the other and oiiset from the plane passing through theaxis of its crank shaft parallel to its own axis; 'a relatively shortrod connecting its piston and crank, whereby said piston is speedierthan the other on the out-stroke and connecting them, air ports 1n theother, a

slower on @the n-srake; ports foy air inkxts controlled by the langerpston; and pome; or @xbm-1st, opened by the smalmpsiion as soon as theam* pons and cosa by it mfier thm f l?. Bn n'rm combuston engine, imcombinuioxna a eylnder'and a hmmber com nected therewih by acontinuously open passage having a. @foss sectional area, hess than that0 said cyndcr, but suceu't 01" hhs ,main body @f gases to pass thmugh itimder nmnm opm'ung conc'iions Without any ma'l'ml nceas@ o pressure? apsxm in the cylinders; means to project n, spray of liquid fuel into"che chamber at th@ time of combustion; and displacing means, act-ingsmutzmeously wih the 'projecting means whereby the, si ue sprayis-dxected jtO ffm'mlt pzurts of the main body of engine contentssuccessively.,

Sgned by me at Boston, day of January, 1912.

MERL R. VULFARD.

Mass., this 30th itnesscs @www KENT, Josmli T. BRENNAN.

